Posted by Dick Hosmer on Tuesday, 28 February 2017, at 10:33 a.m., in response to USISS M1870 Rifle: cut down, posted by Rich F. on Monday, 27 February 2017, at 2:55 p.m.

I've always wondered about the "three click" tumblers occasionally encountered in thick lockplates - where did they come from, since that change did not occur until after the thick plates were history? Did Bannerman - or someone else - actually make them? Why?